Rubber spreading machine



May 3, 1938. A. s. STUMPP RUBBER SPREADING' MACHINE Filed Sept. 1, 1934MmmE zU 02.12.55

i INVENT OR. @m1/,0ny 5. 5,1m

BY M

ATTORNEY.

Patented May 3, 1938 RUBBER SPREADING MACHINE I Anthony Samuel Stumm),Fairfield, Conn., assignor to E.- I.. du Pont de Nemours & Company,Wilmington, Del., a corporation of Delaware Application September 1,1934, Serial No. 742,431

3 Claims.

This invention relates to the coating of fibrous sheet materials andmore particularly to an improved machine and method for coating andtreating such coated fibrous sheets.

In the productionof certain types of rubber composition coated fabricsor so called rubberized fabrics it is common practice to apply therubber composition film to the fabric by spreading a rubber dough orcement under a spreader knife and then evaporating the solvent bypassing the coated fabric over steamcoils or other suitable means offurnishing heat. By rubber dough or cement is meant a dispersion of arubber cornposition in gasoline or other suitable dispersing medium.After the application of the rubber composition and the evaporation ofthe solvent, the rubberized fabric or base is transferred to anothermachine where talc, mica, starch or a similar dusting agent is appliedto the rubberized 20 surface. This application is either for the purposeof preventing the sticking of the rubberized surface or for imparting aspecial finish. After this treatment the rubberized material isvulcanized in the customary manner by exposure to sulphur chloridevapors, by contact with sulphur chloride liquor, by dry heat or in otherknown ways.

This invention has as an object the provision of a machine for theapplication -of a rubber composition film and the finishing material astalc, starch, etc., in a continuous manner on a single machine. Afurther object is to provide a compact machine for carrying on theprocess of applying a rubber coating to a textile fabric and finishingthe rubberized fabric by dusting agents in a single operation.

These objects are accomplished by the following invention in which thefibrous base is coated with a rubber composition, subjected to heat toremove the volatile material used in the rubber composition, passingunder a dusting agent applicator which applies an excess of the dustingagent to the surface of the coated fabric and removing the excessdusting material by means of a rotating brush and suction.

The drawing shows diagrammatically the machine assembly set up foroperation. In the drawing I is a roll of fabric which is to be coated, 2indicates a tension drum, 3 isa coating knife, 4 represents a coatingroll, 5 indicates steam coils for supplying heat, 6 is a rigid knife forspreading the dusting agent and 'lis the position of the dusting agentin front of the knife 6; 8 indicates the overflow box for dustingmaterial, 9 the rotating brush, I the dusting chamber, II the exit ductleading to exhaust fan and cyclone separator, I2 the additional steamcoils for supplying heat and I3 is the wind up roll of coated and dustedmaterial.

Reference to the accompanying diagrammatic drawing will illustrate moreclearly the invention. In the operation of the machine assembly thefibrous base material is unwound from the roll I and is passed over thecoating roll 4', and under the coating knife 3. 'I'he rubber compositionwhich is to be spread on the base piles up as a bank in front of theknife. The coated base material is then passed over steam coils Where itis heated, to remove the volatile material from the coating composition.After passing over the -heating coils the coated base is passed underthe rigid knife 6 in front of which is a bank of dusting material. Herethe coated side of the base is covered with an excess of the dustingmaterial which is later removed as it passes over or around the pulldrum 2 and, is brushed by the rotating brush 9. The excess dustingpowder falls or is swept into the brushing chamber I 0, and thenexhausted through the exit II to a cyclone separator (not shown). Thedusted base after passing over the brushing chamber I0 again is passedover steam heated coils to dry it further and then to the wind up rollI3. From here the material is taken to the vulcanizing equipment orsubjected to other treatments well known in the industry. Thevulcanizing and other operations form no part of this invention sincethese procedures are well known in the art.

The thickness of the film of rubber composition to be applied to thefabric is determined by the clearance between the knife 3 and the basepassing over the roll 4. The excess finishing or dusting agent 'Iapplied to the coated base falls from the edges of the material as itpasses under the knife 6 into the receiver 8 from whence it is returnedto the position as shown at I as needed. The finishing agent asrecovered by the cyclone separator (not shown)` can, of course, bereused as its quality has not been impaired. The bristle brush 9 rotatesin a direction opposite to that of the travel of the coated base towhich the finishing agent has been applied. 'Ihis brush is so arrangedas to extend across the entire width of the material which is beingbrushed.

Different embodiments of this invention may be made without departingfrom the spirit thereof so that no limitation is made to the specificembodiment except as found in the appended claims. Modifications will bereadily apparent to those skilled in the art, for example, means forheating the coated base may be a steam chest or electrically heatedplates in place of the steam coils. The position of the brushing chambermay be changed to suit conditions of arrangement and position, and twobrushing rolls may be used in place of one if desired. l

The machine of the invention has been successfully used for the coatingand nnishing 'of Vfibrous bases. in a single operation as described.

This invention presents as an advantage over prior art the coating andfinishing of rubber coated fibrous base material in a single unitoperation in place of the two operations now necessary. It furtherprovides a more compact unit for coating and finishing, requiring lessfloor space which is an important item i'n any production operation. Theeconomic advantage of the single unit operation in permitting increasedproduction and lower labor costs will be readily apparent to thoseskilled in the art. This also applies to the requirements of less oorspace for the machine of the invention than is required for the twomachines as now used.

A further advantage is that the single unit machine requires less powerfor operation than is required for single disconnected units. Theeconomic advantage in lowered production costs 'is readily apparent. Afurther advantage is the elimination of the possibility of the coatedbase sticking together when rolled up after being coated due to thepresence of the nishing agent on the otherwise sticky coating.

I claim:

1. A machine for coating and nishing rubber composition-coated fibrousbase material comprising an unbatchroll, a coating knife for applying arubber composition, means for drying the spread composition, a knife forspreading an excess of starch on the rubber composition, a brush forremoving the excess starch, means for withdrawing the starch from thebrushing stage, and means to heat the coated material after it has leftthe said brush.

2. In a machine for continuously coating fibrous sheet material anunbatch roll, means comprising a coacting coating knife and coating rollfor applying a coating comprising rubber and volatile material to thefibrous sheet material. means for heating the atmosphere about thecoated brous material after it leaves the rubber coating means to removea portion of the volatile material, means including an idler roll, apull roll and a spreader knife for spreading a dusting powder on thecoated partially dried ilbrous sheet material in excess cf the amountvrequired to prevent sticking of the coated surface, means comprising arotating brushing device for removing the excess of the dusting powderover the amount required to prevent sticking of the coated surface.means to collect nd carry away the excess dusting powder. w L forheating the atmosphere about the dus 1 fibrous sheet material to removethe ex a. volatile material and a wind-up roll, the said elements of themachine being arranged to operate on the continuous sheet of nbrcusmaterial in the order named.

3. The machine of claim 2 wherein the second heating means is placedunderneath the first heating means.

- ANTHONY SAMUEL STUMPP.

